Water quality is deteriorating all over the world, where pollution contaminates many natural water resources. According to updated data revealed in a recent “UN water report”, the world is on the verge of a water crisis. Currently, over 2 billion citizens around the world have no access to safe drinking water. As a result 80% of illness and death in underdeveloped countries is due to water contamination. The report stated that managing drinking water is essential if the world is to achieve sustainable living.
Hence, safe drinking water is becoming a very valuable recourse, one that should be dealt with great care, especially when planning a water treatment system. Drinking water is a valuable resource, especially after a partial purification or complete purification stages have been applied on it. There are particle filters, activated carbon filters, ozone based purification, reverse osmosis (RO) based purification, Ultra Violet (UV) based purification, processing and others.
Current art provides a variety of water purification methods each having drawbacks, such as partial purification, high cost and producing a large quantity of wasted gray water. Farther more, in developed countries there is a current trend of banning the usage of bottled water in plastic bottles. Major cities around the world have banned already bottled water in the public domains. For example, London banned the usage of bottled water in the public domain on Jan. 1, 2010. As for this date it is illegal to sell plastic bottles containing water on the streets, shopping malls, schools etc. As a result of such laws, there is a great need for an alternative solution for drinking water in the public domain. The term “gray water” as used herein refers to waste water that is a product of one or a combination of the following sources: drain water as a result of the purification element of the system, water from a drinking water faucet, water from the bottle disinfection procedure and drained, leaks within the tubing of the system and a result of system cleaning processes using back flush, to clean the filters and/or ion-exchange and adsorption systems. Currently, an individual wanting to drink water in public places such as on the street/school/mall etc, is presented with two main options:                a) Tap water from fountains (which people don't trust and can be even less safe than tap water):                    Not safe due to various possible water contaminations, such as bacteria, chemicals, etc.                        b) A common solution for drinking water on the street is by consuming mineral water:                    Not safe due to various possible water contaminations, such as: Toxic chemicals like BPA, leached from plastic bottles. Bottled water is a habitat for microbes.            Not Green: the bottled water industry is responsible for great damage to the environment. The bottled water industry produces an annual Carbon foot print of 25,000,000 tons, uses 170,000,000 barrels of oil and only 10%-14% of the bottles wind up being recycled. In addition, transporting and marketing these bottles creates an additional environmental damage. For example, 25% of the bottled water is flown around the world. That's a significant additional carbon print.            Very expensive, substantially more expensive than tap water.                        
There is a growing global demand for saving energy and resources. In light of the global ecological condition, a quick reduction of pollution levels (carbon foot print) and an increase in water savings are urgently needed.
There is therefore a need for and it would be advantageous to have a system providing a sustainable, environmental-friendly, healthy and cost effective solution for consuming water in public spaces, a system that can help minimize ecological and health hazards as well. Water purification systems for public and household use are well known in the art, including patents that describe waste water circulation but to a limited extent in order to reduce the drainage flow. In addition the waste water recycling is targeted to drain water which water is a byproduct of the purification process. The circulation issue was addressed in U.S. Pat. Nos. 4,599,166 and 6,099,735 where water is circulated and treated with ozone in order to eliminate biological mater within suspended water vessel. U.S. Pat. No. 5,997,738 provides a RO system that recycles part of the RO drain water. U.S. Pat. No. 4,554,688 presents again similar idea for heating/cooling systems. Patent CN200951965 Y where there is up to 100% waste water recycling.
However there is no suggestion to eliminate the waste water completely in a drinking water vending and/or dispenser machine. waste water in a drinking water vending machine could be a product of one or a combination of the following sources: drain water as a result of the purification element of the system, water streaming out of a drinking water faucet, water streaming from the bottle disinfection procedure and drained, leaks within the tubing of the system and a result of system cleaning processes using back flush, to clean the filters and/or ion-exchange and Back flush, which is a reverse flow of the water in a system, in order to clean the system from accumulated contaminating elements, is described in USP application 20020008068 by Gary L. Anderson as a method for cleaning a fluid filter.